Ileal and total tract nutrient digestibility in blue foxes (Alopex lagopus) fed extruded diets containing different protein sources

This study compared apparent ileal and total tract digestibility of macronutrients and amino acids in blue foxes (Alopex lagopus) fed dry extruded diets. The control diet contained fish meal as the main protein source, while in the other diets 50% of the fish meal protein was replaced by not de-hulled solvent-extracted soybean meal, meat meal or bacterial protein meal. Ileal digestibility was obtained with animals modified with ileorectal anastomosis (IRA method). There were no significant differences in the average digestibility of CP, Lys, Trp, Val, Ala or Glu between IRA modified and intact animals. Average ileal digestibilities of His, Thr, Asp, Cys, Gly, Hyp, Pro, Ser, starch and total carbohydrates (CHO) were significantly lower compared with total tract values. Average ileal digestibility of Arg, Ile, Leu, Met, Phe, Tyr and crude fat was significantly higher than total tract digestibility. Digestibility measured in IRA modified animals showed less variability compared with values from intact animals. There were significant differences among diets in ileal as well as total tract digestibility of orude protein, most amino acids, starch and CHO, and in ileal digestibility of crude fat. Ileal crude protein digestibility of the diets ranged from 81.0-86.4% and total tract digestibility from 82.5-86.4%. Ileal amino acid digestibilities ranged from 70.1 (Asp) to 93.3% (Arg) and total tract values ranged from 72.8 (Cys) to 92.2% (Arg). Both ileal and total tract digestibilities of crude protein and most amino acids were significantly lower for diets containing meat meal or bacterial protein meal compared with the control fish meal-based diet and the diet with soybean meal. Although ileal digestibility may be more accurate than total tract digestibility in estimating the protein and amino acid supply in blue foxes, total tract digestibility may be acceptable because of numerically small differences between ileal and total tract digestibilities for protein and most amino acids. It was further concluded that ileal digestibilities of starch and CHO in the blue fox are lower than corresponding total tract digestibilities.     

Three Decades of Farmed Escapees in the Wild: A Spatio-Temporal Analysis of Atlantic Salmon Population Genetic Structure throughout Norway

Each year, hundreds of thousands of domesticated farmed Atlantic salmon escape into the wild. In Norway, which is the world’s largest commercial producer, many native Atlantic salmon populations have experienced large numbers of escapees on the spawning grounds for the past 15–30 years. In order to study the potential genetic impact, we conducted a spatio-temporal analysis of 3049 fish from 21 populations throughout Norway, sampled in the period 1970–2010. Based upon the analysis of 22 microsatellites, individual admixture, F_ST and increased allelic richness revealed temporal genetic changes in six of the populations. These changes were highly significant in four of them. For example, 76% and 100% of the fish comprising the contemporary samples for the rivers Vosso and Opo were excluded from their respective historical samples at P = 0.001. Based upon several genetic parameters, including simulations, genetic drift was excluded as the primary cause of the observed genetic changes. In the remaining 15 populations, some of which had also been exposed to high numbers of escapees, clear genetic changes were not detected. Significant population genetic structuring was observed among the 21 populations in the historical (global F_ST = 0.038) and contemporary data sets (global F_ST = 0.030), although significantly reduced with time (P = 0.008). This reduction was especially distinct when looking at the six populations displaying temporal changes (global F_ST dropped from 0.058 to 0.039, P = 0.006). We draw two main conclusions: 1. The majority of the historical population genetic structure throughout Norway still appears to be retained, suggesting a low to modest overall success of farmed escapees in the wild; 2. Genetic introgression of farmed escapees in native salmon populations has been strongly population-dependent, and it appears to be linked with the density of the native population.     

The contribution of Aeromonas salmonicida extracellular products to the induction of inflammation in Atlantic salmon (Salmo salar L.) following vaccination with oil-based vaccines

Intraperitoneal injection of Atlantic salmon with oil-based vaccines often results in severe side effects. Aeromonas salmonicida subspecies salmonicida, a primary antigen in the vaccines, produces extracellular products (ECPs) that are included in the formulation but the role of ECPs in inducing side effects is not well understood. In the present study, we evaluated the contribution of ECPs to early inflammatory reactions since early events determine the outcome of inflammation. Five groups of Atlantic salmon pre-smolts were injected intraperitoneally with one of the following preparations: (1) A. salmonicida water-in-oil (w/o) containing standard amounts of ECPs; (2) A. salmonicida (w/o) with ECPs concentrated five times; (3) A. salmonicida (w/o) without ECPs (ECPs were removed by washing and re-suspension of the bacteria prior to formulation); (4) w/o only (without antigens), and (5) physiological saline. Tissue sections of the injection site (pyloric caeca and surrounding areas) were collected at monthly intervals for 4 months in phosphate buffered formalin and processed for light microscopy. Computer-assisted microscopy with the help of Image Pro analysis program was used to measure the area of inflammation on H&E stained sections. Differential cell counts of leucocytes involved in the inflammatory reaction were also done based on morphology. Overall results show that fish injected with vaccines containing concentrated amounts of ECPs displayed a higher average area of inflammation compared to all other groups. In contrast, washed preparations induced mild reactions compared to vaccines containing either standard or concentrated ECPs. Mild, non-persistent reactions were observed in the group injected with oil adjuvant only. Neutrophils were persistent in inflammations induced by all preparations except w/o only. No inflammatory reactions were observed in the group injected with PBS. The results suggest that ECPs are pro-inflammatory in Atlantic salmon. It is anticipated that ECPs are more readily exposed to inflammatory cells than the bacterial cells themselves during early stages of inflammation because of their orientation at the water-oil interface. The results indicate that ECPs of A. salmonicida play an important role in the induction of early inflammatory reactions. It is also documented that the combination of antigens with oil adjuvants, and not the adjuvants alone, is the inducer of strong inflammatory reactions in Atlantic salmon.     

Enhanced antitumor activity and selectivity of lactoferrin-derived peptides.

A number of peptide analogs derived from the N-terminal alpha-helical region of bovine lactoferrin (LFB 14-31), were designed in order to investigate how deviating numbers and positions of positively charged residues and numbers of aromatic residues affected their activity against prokaryotic, normal and transformed eukaryotic cells. Most of the LFB derivatives were highly active against both Escherichia coli and Staphylococcus aureus. The peptides were more active against the tumor cell lines MethA, HT-29 and MT-1 than normal eukaryotic cells. The peptides that were most active against the tumor cell lines had all cationic residues concentrated in one sector of the helical structure. These peptides were less selective against the tumor cell lines than against normal fibroblasts. Quantitative structure-activity relationship studies showed that certain structural parameters affected toxicity against the tumor cell lines more than against fibroblasts. Peptides encompassing these parameters were slightly less active against tumor cells, but gained significant selectivity.     

Timing of bud set in Picea abies is regulated by a memory of temperature during zygotic and somatic embryogenesis

It has been shown previously that height growth and bud phenology are influenced by the temperature during zygotic embryogenesis in Picea abies. To test whether this phenomenon operates within individual plants, clones produced through somatic embryogenesis were used. Seeds were from a full-sib family produced in both a cold (outdoor) and a warm (inside a glasshouse) environment. Embryogenic clones derived from mature zygotic embryos from both crossing environments were cultured at 18, 23 and 28 degrees C during the proliferation and embryo maturation steps. After the second growing season in a glasshouse, plants from the warm seed production environment were taller and had significantly later bud set. For the first time, it is also shown that plants are influenced by the in vitro temperature during somatic embryo development. The warmer the temperature, the later the plants formed terminal buds. The differences were similar to those produced by a provenance separation of 4-6 degrees of latitude. The results indicate that there exists a mechanism in P. abies that operates during embryo development and adjusts the timing of bud set in accordance with the temperature conditions in which the mother tree lives. This in turn counteracts negative effects of gene flow among populations located along altitudinal and latitudinal gradients.     

Assessing invasion criteria in fine needle aspirates from breast carcinoma diagnosed as DICS or invasive carcinoma: can we identify an invasive component in addition to DCIS?

OBJECTIVE: To evaluate invasion criteria in fine needle aspiration cytology (FNAC) of histologically diagnosed breast ductal carcinoma in situ (DCIS) and invasive carcinoma and to evaluate their usefulness in identifying an invasive component in addition to DCIS. STUDY DESIGN: The material consisted of 331 smears diagnosed as suspicious for or consistent with DCIS and in which histology had shown either DCIS or invasive ductal carcinoma. All smears were reevaluated for the following invasion criteria: invasion of fat or fibrous tissue fragments, fibroblast proliferation, cell-poor elastoid tissue fragments, tubular structures and intracytoplasmic vacuoles. RESULTS: All invasion criteria except cytoplasmic vacuoles correlated with invasiveness, but none of them were found exclusively in invasive lesions. Pseudoinvasion in fibrous or fatty tissue fragments were found in 8 cases of histologic pure DCIS. One DCIS (0.4%) revealed > or = 2 invasion features as well as 22 invasive carcinomas (20.7%), representing 7.4% of all cases. CONCLUSION: Using established invasion criteria, practically no pure DCIS lesion will be diagnosed as invasive on FNAC, but one will identify only a subset of cases harboring an invasive component.     

Bacterial protein meal in diets for pigs and minks: comparative studies on protein turnover rate and urinary excretion of purine base derivatives

The effect of increasing the dietary content of bacterial protein meal (BPM) on protein turnover rate, and on nucleic acid and creatinine metabolism in growing minks and pigs was investigated in two experiments. In each experiment, 16 animals were allocated to four experimental diets. The diets containing no BPM served as controls, i.e. for minks diet M1, for pigs P1; the experimental diets contained increasing levels of BPM to replace fish meal (minks) or soybean meal (pigs), so that up to 17% (P2), 20% (M2), 35% (P3), 40% (M3), 52% (P4), and 60% (M4) of digestible N was BPM derived. Protein turnover rate was measured by means of the end-product method using [15N]glycine as tracer and urinary nitrogen as end-product. In minks, protein flux, synthesis, and breakdown increased significantly with increasing dietary BPM. In pigs, diet had no observed effect on protein turnover rate. The intake of nucleic acid nitrogen (NAN) increased from 0.15 g/kg W0.75 on M1 to 0.26 g/kg W0.75 on M3 and M4 in the mink experiment, and from 0.08 g/kg W0.75 on P1 to 0.33 g/kg W0.75 on P4 in the pig experiment. Increased NAN intake led, in both experiments, to increased allantoin excretion. Analysis of species effects showed that minks excreted 1.72 mmol/ kg W0.75 of allantoin, significantly more than the 0.95 mmol/kg W0.75 excreted by pigs. In minks, approximately 96% of the excreted purine base derivatives consisted of allantoin, whereas in pigs approximately 93% did. Thus, increasing the dietary content of BPM increased protein turnover rate in minks but not in pigs, and allantoin excretion increased with increasing dietary BPM although it seemed that mink decomposed purine bases to their end-product more completely than pigs did. Collectively these data show that BPM is a suitable protein source for pigs and mink, and recorded differences between species were to a large extent due to differences in protein retention capacity and muscle mass.